Microstructural change in austenitic Fe-30.0wt%Mn-7.8wt%Al-1.3wt%C initiated by spinodal decomposition and its influence on mechanical properties
Microstructural change in austenitic Fe-30.0wt%Mn-7.8wt%Al-1.3wt%C initiated by spinodal decomposition and its influence on mechanical properties
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DOI：
10.1016/s1359-6454(97)00201-2
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发表时间：
1997-12-01
期刊：
影响因子：
9.4
通讯作者：
Yoon, JC
中科院分区：
文献类型：
--
作者：
Choo, WK;Kim, JH;Yoon, JC
采用透射电子显微镜（TEM）和X射线衍射研究了过饱和奥氏体Fe-30.0wt%Mn-7.8wt%Al-1.3wt%C合金在823 K时效时的显微组织变化。人们已努力将调制波长行为与导致立方卡帕碳化物 (Fe,Mn)(3)AlCx 形成的旋节线分解过程中的机械性能联系起来。与调制波长粗化行为同时，时效过程中显微硬度和拉伸强度在两个阶段中增加。第一阶段强化与缓慢生长旋节线分解一致，而第二阶段强化发生在有序 kappa' 粒子的 Lifshitz-Slyozov-Wagner (LSW) 生长阶段。通过对合金进行优化的时效处理，可以获得高达1080 MPa的高屈服强度和31.5%的优异延伸率。进一步时效后，合金迅速软化，由于形成由不连续粗化的κ碳化物和转变的α铁素体相组成的晶界片状团，其延伸率急剧恶化。 (C) 1997 Acta Metallurgica Inc.
The microstructural change of supersaturated austenitic Fe-30.0wt%Mn-7.8wt%Al-1.3wt%C alloy on ageing at 823 K has been investigated by transmission electron microscopy (TEM) and X-ray diffraction. Efforts to correlate the modulation wavelength behavior with mechanical proper ties in the process of spinodal decomposition leading to the cubic kappa'-carbide (Fe,Mn)(3)AlCx formation have been made. In parallel with the modulation wavelength coarsening behavior, both the microhardness and the tensile strength increase in two stages during ageing. The first stage strengthening coincides wi th the slow growth spinodal decomposition, while the second occurs at the Lifshitz-Slyozov-Wagner (LSW) growth stage of ordered kappa' particles. By the optimal ageing treatment of the alloy, a high yield strength up to 1080 MPa with an excellent 31.5% elongation can be attained. After further ageing, the alloy softened rapidly, and its elongation deteriorated drastically due to the formation of the grain boundary lamellar colonies composed of discontinuously coarsened kappa carbide and transformed alpha ferrite phases. (C) 1997 Acta Metallurgica Inc.